The United States Postal Service (USPS) uses a sorting system that arranges and positions letter mail into specially designed cartridges. The cartridges are designed to interface with the sorting system, and to maintain the orientation and position of the sorted letter mail. The cartridges are relatively expensive to manufacture. A typical cartridge contains components such as springs, levers and guides that interact with one another for the cartridge to function properly, retaining letter mail as loaded into the cartridge.
The sorting system is located at a central or regional processing center operated by the USPS. Approximately, 500 million pieces of letter mail a day may be sorted and positioned into the cartridges. Subsequent to the sorting process, the cartridges loaded with sorted letter mail are shipped from the regional processing center to other locations from which the mail is distributed to the population. A concern in transporting the cartridges from the regional processing center is the possibility that the cartridges may not be returned or if returned the cartridges may have been damaged during the transportation process. Another concern, is the relatively high transportation costs associated with moving the cartridges in part due to the weight of the cartridges, which are generally manufactured of metal.
Accordingly, there is a need for a tray loader or transfer apparatus that transfers letter mail located in a cartridge to a conventional lighter and less costly tray. Conventional letter mail trays may have different dimensions than a mail cartridge consequently any transfer apparatus should be able to handle both types of letter mail receptacles. Also there is a need to maintain the original orientation of the letter mail during the transfer process between the cartridge and the conventional tray. These and other needs are addressed by the tray loader of the present invention.